mdw@git.distorted.org.uk Git - adns/blob - src/setup.c

   1 /*
   2  * setup.c
   3  * - configuration file parsing
   4  * - management of global state
   5  */
   6 /*
   7  *  This file is part of adns, which is
   8  *    Copyright (C) 1997-2000,2003,2006  Ian Jackson
   9  *    Copyright (C) 1999-2000,2003,2006  Tony Finch
  10  *    Copyright (C) 1991 Massachusetts Institute of Technology
  11  *  (See the file INSTALL for full details.)
  12  *
  13  *  This program is free software; you can redistribute it and/or modify
  14  *  it under the terms of the GNU General Public License as published by
  15  *  the Free Software Foundation; either version 2, or (at your option)
  16  *  any later version.
  17  *
  18  *  This program is distributed in the hope that it will be useful,
  19  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  *  GNU General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU General Public License
  24  *  along with this program; if not, write to the Free Software Foundation,
  25  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  26  */
  27
  28 #include <stdlib.h>
  29 #include <errno.h>
  30 #include <limits.h>
  31 #include <unistd.h>
  32 #include <fcntl.h>
  33
  34 #include <sys/types.h>
  35 #include <netdb.h>
  36 #include <sys/socket.h>
  37 #include <netinet/in.h>
  38 #include <arpa/inet.h>
  39
  40 #include "internal.h"
  41
  42 static void readconfig(adns_state ads, const char *filename, int warnmissing);
  43
  44 static void addserver(adns_state ads, const struct sockaddr *sa, int n) {
  45   int i;
  46   adns_rr_addr *ss;
  47   const struct sockaddr_in *sin;
  48
  49   assert(sa->sa_family==AF_INET); /* for inet_ntoa */
  50   sin= (const void *)sa;
  51
  52   for (i=0; i<ads->nservers; i++) {
  53     if (adns__sockaddr_equal_p(sa, &ads->servers[i].addr.sa)) {
  54       adns__debug(ads,-1,0,"duplicate nameserver %s ignored",
  55                   inet_ntoa(sin->sin_addr));
  56       return;
  57     }
  58   }
  59
  60   if (ads->nservers>=MAXSERVERS) {
  61     adns__diag(ads,-1,0,"too many nameservers, ignoring %s",
  62                inet_ntoa(sin->sin_addr));
  63     return;
  64   }
  65
  66   ss= ads->servers+ads->nservers;
  67   assert(n <= sizeof(ss->addr));
  68   ss->len = n;
  69   memcpy(&ss->addr, sa, n);
  70   ads->nservers++;
  71 }
  72
  73 static void freesearchlist(adns_state ads) {
  74   if (ads->nsearchlist) free(*ads->searchlist);
  75   free(ads->searchlist);
  76 }
  77
  78 static void saveerr(adns_state ads, int en) {
  79   if (!ads->configerrno) ads->configerrno= en;
  80 }
  81
  82 static void configparseerr(adns_state ads, const char *fn, int lno,
  83                            const char *fmt, ...) {
  84   va_list al;
  85
  86   saveerr(ads,EINVAL);
  87   if (!ads->logfn || (ads->iflags & adns_if_noerrprint)) return;
  88
  89   if (lno==-1) adns__lprintf(ads,"adns: %s: ",fn);
  90   else adns__lprintf(ads,"adns: %s:%d: ",fn,lno);
  91   va_start(al,fmt);
  92   adns__vlprintf(ads,fmt,al);
  93   va_end(al);
  94   adns__lprintf(ads,"\n");
  95 }
  96
  97 static int nextword(const char **bufp_io, const char **word_r, int *l_r) {
  98   const char *p, *q;
  99
 100   p= *bufp_io;
 101   while (ctype_whitespace(*p)) p++;
 102   if (!*p) return 0;
 103
 104   q= p;
 105   while (*q && !ctype_whitespace(*q)) q++;
 106
 107   *l_r= q-p;
 108   *word_r= p;
 109   *bufp_io= q;
 110
 111   return 1;
 112 }
 113
 114 static void ccf_nameserver(adns_state ads, const char *fn,
 115                            int lno, const char *buf) {
 116   struct sockaddr_in sin;
 117
 118   memset(&sin,0,sizeof(sin));
 119   sin.sin_family= AF_INET;
 120   sin.sin_port= htons(DNS_PORT);
 121   if (!inet_aton(buf,&sin.sin_addr)) {
 122     configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
 123     return;
 124   }
 125   adns__debug(ads,-1,0,"using nameserver %s",inet_ntoa(sin.sin_addr));
 126   addserver(ads,(const struct sockaddr *)&sin,sizeof(sin));
 127 }
 128
 129 static void ccf_search(adns_state ads, const char *fn,
 130                        int lno, const char *buf) {
 131   const char *bufp, *word;
 132   char *newchars, **newptrs, **pp;
 133   int count, tl, l;
 134
 135   if (!buf) return;
 136
 137   bufp= buf;
 138   count= 0;
 139   tl= 0;
 140   while (nextword(&bufp,&word,&l)) { count++; tl += l+1; }
 141
 142   newptrs= malloc(sizeof(char*)*count);
 143   if (!newptrs) { saveerr(ads,errno); return; }
 144
 145   newchars= malloc(tl);
 146   if (!newchars) { saveerr(ads,errno); free(newptrs); return; }
 147
 148   bufp= buf;
 149   pp= newptrs;
 150   while (nextword(&bufp,&word,&l)) {
 151     *pp++= newchars;
 152     memcpy(newchars,word,l);
 153     newchars += l;
 154     *newchars++ = 0;
 155   }
 156
 157   freesearchlist(ads);
 158   ads->nsearchlist= count;
 159   ads->searchlist= newptrs;
 160 }
 161
 162 static void ccf_sortlist(adns_state ads, const char *fn,
 163                          int lno, const char *buf) {
 164   const char *word;
 165   char tbuf[200], *slash, *ep;
 166   const char *maskwhat;
 167   struct sortlist *sl;
 168   int l;
 169   int af= AF_UNSPEC;
 170   int initial= -1;
 171
 172   if (!buf) return;
 173
 174   ads->nsortlist= 0;
 175   while (nextword(&buf,&word,&l)) {
 176     if (ads->nsortlist >= MAXSORTLIST) {
 177       adns__diag(ads,-1,0,"too many sortlist entries,"
 178                  " ignoring %.*s onwards",l,word);
 179       return;
 180     }
 181
 182     if (l >= sizeof(tbuf)) {
 183       configparseerr(ads,fn,lno,"sortlist entry `%.*s' too long",l,word);
 184       continue;
 185     }
 186
 187     memcpy(tbuf,word,l); tbuf[l]= 0;
 188     slash= strchr(tbuf,'/');
 189     if (slash) *slash++= 0;
 190
 191     sl= &ads->sortlist[ads->nsortlist];
 192     if (!inet_aton(tbuf, &sl->base.v4)) {
 193       configparseerr(ads,fn,lno,"invalid address `%s' in sortlist",tbuf);
 194       continue;
 195     }
 196     af= AF_INET;
 197
 198     if (slash) {
 199       if (slash[strspn(slash, "0123456789")]) {
 200         maskwhat = "mask";
 201         if (!inet_aton(slash, &sl->mask.v4)) {
 202           configparseerr(ads,fn,lno,"invalid mask `%s' in sortlist",slash);
 203           continue;
 204         }
 205       } else {
 206         maskwhat = "prefix length";
 207         initial= strtoul(slash,&ep,10);
 208         if (*ep || initial>adns__addr_width(af)) {
 209           configparseerr(ads,fn,lno,"mask length `%s' invalid",slash);
 210           continue;
 211         }
 212         adns__prefix_mask(af, initial, &sl->mask);
 213       }
 214     } else {
 215       maskwhat = "implied prefix length";
 216       initial= adns__guess_prefix_length(af, &sl->base);
 217       if (initial < 0) {
 218         configparseerr(ads,fn,lno, "network address `%s'"
 219                        " in sortlist is not in classed ranges,"
 220                        " must specify mask explicitly", tbuf);
 221         continue;
 222       }
 223       adns__prefix_mask(af, initial, &sl->mask);
 224     }
 225
 226     if (!adns__addr_match_p(af,&sl->base, af,&sl->base,&sl->mask)) {
 227       if (initial >= 0) {
 228         configparseerr(ads,fn,lno, "%s %d in sortlist"
 229                        " overlaps address `%s'",maskwhat,initial,tbuf);
 230       } else {
 231         configparseerr(ads,fn,lno, "%s `%s' in sortlist"
 232                        " overlaps address `%s'",maskwhat,slash,tbuf);
 233       }
 234       continue;
 235     }
 236
 237     sl->af= af;
 238     ads->nsortlist++;
 239   }
 240 }
 241
 242 static void ccf_options(adns_state ads, const char *fn,
 243                         int lno, const char *buf) {
 244   const char *word;
 245   char *ep;
 246   unsigned long v;
 247   int l;
 248
 249   if (!buf) return;
 250
 251   while (nextword(&buf,&word,&l)) {
 252     if (l==5 && !memcmp(word,"debug",5)) {
 253       ads->iflags |= adns_if_debug;
 254       continue;
 255     }
 256     if (l>=6 && !memcmp(word,"ndots:",6)) {
 257       v= strtoul(word+6,&ep,10);
 258       if (l==6 || ep != word+l || v > INT_MAX) {
 259         configparseerr(ads,fn,lno,"option `%.*s' malformed"
 260                        " or has bad value",l,word);
 261         continue;
 262       }
 263       ads->searchndots= v;
 264       continue;
 265     }
 266     if (l>=12 && !memcmp(word,"adns_checkc:",12)) {
 267       if (!strcmp(word+12,"none")) {
 268         ads->iflags &= ~adns_if_checkc_freq;
 269         ads->iflags |= adns_if_checkc_entex;
 270       } else if (!strcmp(word+12,"entex")) {
 271         ads->iflags &= ~adns_if_checkc_freq;
 272         ads->iflags |= adns_if_checkc_entex;
 273       } else if (!strcmp(word+12,"freq")) {
 274         ads->iflags |= adns_if_checkc_freq;
 275       } else {
 276         configparseerr(ads,fn,lno, "option adns_checkc has bad value `%s' "
 277                        "(must be none, entex or freq", word+12);
 278       }
 279       continue;
 280     }
 281     adns__diag(ads,-1,0,"%s:%d: unknown option `%.*s'", fn,lno, l,word);
 282   }
 283 }
 284
 285 static void ccf_clearnss(adns_state ads, const char *fn,
 286                          int lno, const char *buf) {
 287   ads->nservers= 0;
 288 }
 289
 290 static void ccf_include(adns_state ads, const char *fn,
 291                         int lno, const char *buf) {
 292   if (!*buf) {
 293     configparseerr(ads,fn,lno,"`include' directive with no filename");
 294     return;
 295   }
 296   readconfig(ads,buf,1);
 297 }
 298
 299 static void ccf_lookup(adns_state ads, const char *fn, int lno,
 300                        const char *buf) {
 301   int found_bind=0;
 302   const char *word;
 303   int l;
 304
 305   if (!*buf) {
 306     configparseerr(ads,fn,lno,"`lookup' directive with no databases");
 307     return;
 308   }
 309
 310   while (nextword(&buf,&word,&l)) {
 311     if (l==4 && !memcmp(word,"bind",4)) {
 312       found_bind=1;
 313     } else if (l==4 && !memcmp(word,"file",4)) {
 314       /* ignore this and hope /etc/hosts is not essential */
 315     } else if (l==2 && !memcmp(word,"yp",2)) {
 316       adns__diag(ads,-1,0,"%s:%d: yp lookups not supported by adns", fn,lno);
 317       found_bind=-1;
 318     } else {
 319       adns__diag(ads,-1,0,"%s:%d: unknown `lookup' database `%.*s'",
 320                  fn,lno, l,word);
 321       found_bind=-1;
 322     }
 323   }
 324   if (!found_bind)
 325     adns__diag(ads,-1,0,"%s:%d: `lookup' specified, but not `bind'", fn,lno);
 326 }
 327
 328 static const struct configcommandinfo {
 329   const char *name;
 330   void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
 331 } configcommandinfos[]= {
 332   { "nameserver",        ccf_nameserver  },
 333   { "domain",            ccf_search      },
 334   { "search",            ccf_search      },
 335   { "sortlist",          ccf_sortlist    },
 336   { "options",           ccf_options     },
 337   { "clearnameservers",  ccf_clearnss    },
 338   { "include",           ccf_include     },
 339   { "lookup",            ccf_lookup      }, /* OpenBSD */
 340   {  0                                   }
 341 };
 342
 343 typedef union {
 344   FILE *file;
 345   const char *text;
 346 } getline_ctx;
 347
 348 static int gl_file(adns_state ads, getline_ctx *src_io, const char *filename,
 349                    int lno, char *buf, int buflen) {
 350   FILE *file= src_io->file;
 351   int c, i;
 352   char *p;
 353
 354   p= buf;
 355   buflen--;
 356   i= 0;
 357
 358   for (;;) { /* loop over chars */
 359     if (i == buflen) {
 360       adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 361       goto x_badline;
 362     }
 363     c= getc(file);
 364     if (!c) {
 365       adns__diag(ads,-1,0,"%s:%d: line contains nul, ignored",filename,lno);
 366       goto x_badline;
 367     } else if (c == '\n') {
 368       break;
 369     } else if (c == EOF) {
 370       if (ferror(file)) {
 371         saveerr(ads,errno);
 372         adns__diag(ads,-1,0,"%s:%d: read error: %s",
 373                    filename,lno,strerror(errno));
 374         return -1;
 375       }
 376       if (!i) return -1;
 377       break;
 378     } else {
 379       *p++= c;
 380       i++;
 381     }
 382   }
 383
 384   *p++= 0;
 385   return i;
 386
 387  x_badline:
 388   saveerr(ads,EINVAL);
 389   while ((c= getc(file)) != EOF && c != '\n');
 390   return -2;
 391 }
 392
 393 static int gl_text(adns_state ads, getline_ctx *src_io, const char *filename,
 394                    int lno, char *buf, int buflen) {
 395   const char *cp= src_io->text;
 396   int l;
 397
 398   if (!cp || !*cp) return -1;
 399
 400   if (*cp == ';' || *cp == '\n') cp++;
 401   l= strcspn(cp,";\n");
 402   src_io->text = cp+l;
 403
 404   if (l >= buflen) {
 405     adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 406     saveerr(ads,EINVAL);
 407     return -2;
 408   }
 409
 410   memcpy(buf,cp,l);
 411   buf[l]= 0;
 412   return l;
 413 }
 414
 415 static void readconfiggeneric(adns_state ads, const char *filename,
 416                               int (*getline)(adns_state ads, getline_ctx*,
 417                                              const char *filename, int lno,
 418                                              char *buf, int buflen),
 419                               /* Returns >=0 for success, -1 for EOF or error
 420                                * (error will have been reported), or -2 for
 421                                * bad line was encountered, try again.
 422                                */
 423                               getline_ctx gl_ctx) {
 424   char linebuf[2000], *p, *q;
 425   int lno, l, dirl;
 426   const struct configcommandinfo *ccip;
 427
 428   for (lno=1;
 429        (l= getline(ads,&gl_ctx, filename,lno, linebuf,sizeof(linebuf))) != -1;
 430        lno++) {
 431     if (l == -2) continue;
 432     while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
 433     linebuf[l]= 0;
 434     p= linebuf;
 435     while (ctype_whitespace(*p)) p++;
 436     if (*p == '#' || *p == ';' || !*p) continue;
 437     q= p;
 438     while (*q && !ctype_whitespace(*q)) q++;
 439     dirl= q-p;
 440     for (ccip=configcommandinfos;
 441          ccip->name &&
 442            !(strlen(ccip->name)==dirl && !memcmp(ccip->name,p,q-p));
 443          ccip++);
 444     if (!ccip->name) {
 445       adns__diag(ads,-1,0,"%s:%d: unknown configuration directive `%.*s'",
 446                  filename,lno,(int)(q-p),p);
 447       continue;
 448     }
 449     while (ctype_whitespace(*q)) q++;
 450     ccip->fn(ads,filename,lno,q);
 451   }
 452 }
 453
 454 static const char *instrum_getenv(adns_state ads, const char *envvar) {
 455   const char *value;
 456
 457   value= getenv(envvar);
 458   if (!value) adns__debug(ads,-1,0,"environment variable %s not set",envvar);
 459   else adns__debug(ads,-1,0,"environment variable %s"
 460                    " set to `%s'",envvar,value);
 461   return value;
 462 }
 463
 464 static void readconfig(adns_state ads, const char *filename, int warnmissing) {
 465   getline_ctx gl_ctx;
 466
 467   gl_ctx.file= fopen(filename,"r");
 468   if (!gl_ctx.file) {
 469     if (errno == ENOENT) {
 470       if (warnmissing)
 471         adns__debug(ads,-1,0, "configuration file"
 472                     " `%s' does not exist",filename);
 473       return;
 474     }
 475     saveerr(ads,errno);
 476     adns__diag(ads,-1,0,"cannot open configuration file `%s': %s",
 477                filename,strerror(errno));
 478     return;
 479   }
 480
 481   readconfiggeneric(ads,filename,gl_file,gl_ctx);
 482
 483   fclose(gl_ctx.file);
 484 }
 485
 486 static void readconfigtext(adns_state ads, const char *text,
 487                            const char *showname) {
 488   getline_ctx gl_ctx;
 489
 490   gl_ctx.text= text;
 491   readconfiggeneric(ads,showname,gl_text,gl_ctx);
 492 }
 493
 494 static void readconfigenv(adns_state ads, const char *envvar) {
 495   const char *filename;
 496
 497   if (ads->iflags & adns_if_noenv) {
 498     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 499     return;
 500   }
 501   filename= instrum_getenv(ads,envvar);
 502   if (filename) readconfig(ads,filename,1);
 503 }
 504
 505 static void readconfigenvtext(adns_state ads, const char *envvar) {
 506   const char *textdata;
 507
 508   if (ads->iflags & adns_if_noenv) {
 509     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 510     return;
 511   }
 512   textdata= instrum_getenv(ads,envvar);
 513   if (textdata) readconfigtext(ads,textdata,envvar);
 514 }
 515
 516
 517 int adns__setnonblock(adns_state ads, int fd) {
 518   int r;
 519
 520   r= fcntl(fd,F_GETFL,0); if (r<0) return errno;
 521   r |= O_NONBLOCK;
 522   r= fcntl(fd,F_SETFL,r); if (r<0) return errno;
 523   return 0;
 524 }
 525
 526 static int init_begin(adns_state *ads_r, adns_initflags flags,
 527                       adns_logcallbackfn *logfn, void *logfndata) {
 528   adns_state ads;
 529   pid_t pid;
 530
 531   ads= malloc(sizeof(*ads)); if (!ads) return errno;
 532
 533   ads->iflags= flags;
 534   ads->logfn= logfn;
 535   ads->logfndata= logfndata;
 536   ads->configerrno= 0;
 537   LIST_INIT(ads->udpw);
 538   LIST_INIT(ads->tcpw);
 539   LIST_INIT(ads->childw);
 540   LIST_INIT(ads->output);
 541   ads->forallnext= 0;
 542   ads->nextid= 0x311f;
 543   ads->udpsocket= ads->tcpsocket= -1;
 544   adns__vbuf_init(&ads->tcpsend);
 545   adns__vbuf_init(&ads->tcprecv);
 546   ads->tcprecv_skip= 0;
 547   ads->nservers= ads->nsortlist= ads->nsearchlist= ads->tcpserver= 0;
 548   ads->searchndots= 1;
 549   ads->tcpstate= server_disconnected;
 550   timerclear(&ads->tcptimeout);
 551   ads->searchlist= 0;
 552
 553   pid= getpid();
 554   ads->rand48xsubi[0]= pid;
 555   ads->rand48xsubi[1]= (unsigned long)pid >> 16;
 556   ads->rand48xsubi[2]= pid ^ ((unsigned long)pid >> 16);
 557
 558   *ads_r= ads;
 559   return 0;
 560 }
 561
 562 static int init_finish(adns_state ads) {
 563   struct sockaddr_in sin;
 564   struct protoent *proto;
 565   int i, r;
 566
 567   if (!ads->nservers) {
 568     if (ads->logfn && ads->iflags & adns_if_debug)
 569       adns__lprintf(ads,"adns: no nameservers, using IPv4 localhost\n");
 570     memset(&sin, 0, sizeof(sin));
 571     sin.sin_family = AF_INET;
 572     sin.sin_port = htons(DNS_PORT);
 573     sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 574     addserver(ads,(struct sockaddr *)&sin, sizeof(sin));
 575   }
 576
 577   /* we can't cope with multiple transport address families yet */
 578   for (i=0; i<ads->nservers; i++)
 579     assert(ads->servers[i].addr.sa.sa_family==AF_INET);
 580
 581   proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
 582   ads->udpsocket= socket(AF_INET,SOCK_DGRAM,proto->p_proto);
 583   if (ads->udpsocket<0) { r= errno; goto x_free; }
 584
 585   r= adns__setnonblock(ads,ads->udpsocket);
 586   if (r) { r= errno; goto x_closeudp; }
 587
 588   return 0;
 589
 590  x_closeudp:
 591   close(ads->udpsocket);
 592  x_free:
 593   free(ads);
 594   return r;
 595 }
 596
 597 static void init_abort(adns_state ads) {
 598   if (ads->nsearchlist) {
 599     free(ads->searchlist[0]);
 600     free(ads->searchlist);
 601   }
 602   free(ads);
 603 }
 604
 605 static void logfn_file(adns_state ads, void *logfndata,
 606                        const char *fmt, va_list al) {
 607   vfprintf(logfndata,fmt,al);
 608 }
 609
 610 static int init_files(adns_state *ads_r, adns_initflags flags,
 611                       adns_logcallbackfn *logfn, void *logfndata) {
 612   adns_state ads;
 613   const char *res_options, *adns_res_options;
 614   int r;
 615
 616   r= init_begin(&ads, flags, logfn, logfndata);
 617   if (r) return r;
 618
 619   res_options= instrum_getenv(ads,"RES_OPTIONS");
 620   adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
 621   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 622   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 623
 624   readconfig(ads,"/etc/resolv.conf",1);
 625   readconfig(ads,"/etc/resolv-adns.conf",0);
 626   readconfigenv(ads,"RES_CONF");
 627   readconfigenv(ads,"ADNS_RES_CONF");
 628
 629   readconfigenvtext(ads,"RES_CONF_TEXT");
 630   readconfigenvtext(ads,"ADNS_RES_CONF_TEXT");
 631
 632   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 633   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 634
 635   ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
 636   ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
 637
 638   if (ads->configerrno && ads->configerrno != EINVAL) {
 639     r= ads->configerrno;
 640     init_abort(ads);
 641     return r;
 642   }
 643
 644   r= init_finish(ads);
 645   if (r) return r;
 646
 647   adns__consistency(ads,0,cc_entex);
 648   *ads_r= ads;
 649   return 0;
 650 }
 651
 652 int adns_init(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 653   return init_files(ads_r, flags, logfn_file, diagfile ? diagfile : stderr);
 654 }
 655
 656 static int init_strcfg(adns_state *ads_r, adns_initflags flags,
 657                        adns_logcallbackfn *logfn, void *logfndata,
 658                        const char *configtext) {
 659   adns_state ads;
 660   int r;
 661
 662   r= init_begin(&ads, flags, logfn, logfndata);
 663   if (r) return r;
 664
 665   readconfigtext(ads,configtext,"<supplied configuration text>");
 666   if (ads->configerrno) {
 667     r= ads->configerrno;
 668     init_abort(ads);
 669     return r;
 670   }
 671
 672   r= init_finish(ads);  if (r) return r;
 673   adns__consistency(ads,0,cc_entex);
 674   *ads_r= ads;
 675   return 0;
 676 }
 677
 678 int adns_init_strcfg(adns_state *ads_r, adns_initflags flags,
 679                      FILE *diagfile, const char *configtext) {
 680   return init_strcfg(ads_r, flags,
 681                      diagfile ? logfn_file : 0, diagfile,
 682                      configtext);
 683 }
 684
 685 int adns_init_logfn(adns_state *newstate_r, adns_initflags flags,
 686                     const char *configtext /*0=>use default config files*/,
 687                     adns_logcallbackfn *logfn /*0=>logfndata is a FILE* */,
 688                     void *logfndata /*0 with logfn==0 => discard*/) {
 689   if (!logfn && logfndata)
 690     logfn= logfn_file;
 691   if (configtext)
 692     return init_strcfg(newstate_r, flags, logfn, logfndata, configtext);
 693   else
 694     return init_files(newstate_r, flags, logfn, logfndata);
 695 }
 696
 697 void adns_finish(adns_state ads) {
 698   adns__consistency(ads,0,cc_entex);
 699   for (;;) {
 700     if (ads->udpw.head) adns_cancel(ads->udpw.head);
 701     else if (ads->tcpw.head) adns_cancel(ads->tcpw.head);
 702     else if (ads->childw.head) adns_cancel(ads->childw.head);
 703     else if (ads->output.head) adns_cancel(ads->output.head);
 704     else break;
 705   }
 706   close(ads->udpsocket);
 707   if (ads->tcpsocket >= 0) close(ads->tcpsocket);
 708   adns__vbuf_free(&ads->tcpsend);
 709   adns__vbuf_free(&ads->tcprecv);
 710   freesearchlist(ads);
 711   free(ads);
 712 }
 713
 714 void adns_forallqueries_begin(adns_state ads) {
 715   adns__consistency(ads,0,cc_entex);
 716   ads->forallnext=
 717     ads->udpw.head ? ads->udpw.head :
 718     ads->tcpw.head ? ads->tcpw.head :
 719     ads->childw.head ? ads->childw.head :
 720     ads->output.head;
 721 }
 722
 723 adns_query adns_forallqueries_next(adns_state ads, void **context_r) {
 724   adns_query qu, nqu;
 725
 726   adns__consistency(ads,0,cc_entex);
 727   nqu= ads->forallnext;
 728   for (;;) {
 729     qu= nqu;
 730     if (!qu) return 0;
 731     if (qu->next) {
 732       nqu= qu->next;
 733     } else if (qu == ads->udpw.tail) {
 734       nqu=
 735         ads->tcpw.head ? ads->tcpw.head :
 736         ads->childw.head ? ads->childw.head :
 737         ads->output.head;
 738     } else if (qu == ads->tcpw.tail) {
 739       nqu=
 740         ads->childw.head ? ads->childw.head :
 741         ads->output.head;
 742     } else if (qu == ads->childw.tail) {
 743       nqu= ads->output.head;
 744     } else {
 745       nqu= 0;
 746     }
 747     if (!qu->parent) break;
 748   }
 749   ads->forallnext= nqu;
 750   if (context_r) *context_r= qu->ctx.ext;
 751   return qu;
 752 }